## websockify: WebSockets support for any application/server websockify was formerly named wsproxy and was part of the [noVNC](https://github.com/kanaka/noVNC) project. At the most basic level, websockify just translates WebSockets traffic to normal socket traffic. websockify accepts the WebSockets handshake, parses it, and then begins forwarding traffic between the client and the target in both directions. WebSockets payload data is UTF-8 encoded so in order to transport binary data it must use an encoding that can be encapsulated within UTF-8. websockify uses base64 to encode all traffic to and from the client. Also, WebSockets traffic starts with '\0' (0) and ends with '\xff' (255). Some buffering is done in case the data from the client is not a full WebSockets frame (i.e. does not end in 255). ### Websock Javascript library The `include/websock.js` Javascript library library provides a Websock object that is similar to the standard WebSocket object but Websock enables communication with raw TCP sockets (i.e. the binary stream) via websockify. This is accomplished by base64 encoding the data stream between Websock and websockify. Websock has built-in receive queue buffering; the message event does not contain actual data but is simply a notification that there is new data available. Several rQ* methods are available to read binary data off of the receive queue. See the "Wrap a Program" section below for an example of using Websock and websockify as a browser telnet client (`wstelnet.html`). ### Additional websockify features These are not necessary for the basic operation. * Daemonizing: When the `-D` option is specified, websockify runs in the background as a daemon process. * SSL (the wss:// WebSockets URI): This is detected automatically by websockify by sniffing the first byte sent from the client and then wrapping the socket if the data starts with '\x16' or '\x80' (indicating SSL). * Flash security policy: websockify detects flash security policy requests (again by sniffing the first packet) and answers with an appropriate flash security policy response (and then closes the port). This means no separate flash security policy server is needed for supporting the flash WebSockets fallback emulator. * Session recording: This feature that allows recording of the traffic sent and received from the client to a file using the `--record` option. * Mini-webserver: websockify can detect and respond to normal web requests on the same port as the WebSockets proxy and Flash security policy. This functionality is activate with the `--web DIR` option where DIR is the root of the web directory to serve. * Wrap a program: see the "Wrap a Program" section below. ### Implementations of websockify The primary implementation of websockify is in python. There are also alternative implementations in the `other/` subdirectory. Here is the feature support matrix for the the websockify implementations:
Program | websockify | other/websockify | other/websockify.js | other/websockify.rb | other/kumina | VNCAuthProxy 1 |
---|---|---|---|---|---|---|
Language | python | C | Node (node.js) | Ruby | C | python (twisted) |
Multiproc | yes | yes | yes | no | no | yes |
Daemon | yes | yes | no | no | no | yes |
SSL wss | yes 2 | yes | no | no | no | yes |
Flash Policy Server | yes | yes | no | no | yes | no |
Session Record | yes | no | no | no | no | no |
Web Server | yes | no | no | no | no | no |
Program Wrap | yes | no | no | no | no | no |
Multiple Targets | no | no | no | no | yes | no |
Hixie 75 | yes | yes | yes | no | no | no |
Hixie 76 | yes | yes | yes | yes | yes | yes |
IETF/HyBi 07-10 | yes | no | no | no | no | yes |